Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * Copyright (C) 2001, 2002 Sistina Software (UK) Limited. | |
784aae73 | 3 | * Copyright (C) 2004-2008 Red Hat, Inc. All rights reserved. |
1da177e4 LT |
4 | * |
5 | * This file is released under the GPL. | |
6 | */ | |
7 | ||
8 | #include "dm.h" | |
51e5b2bd | 9 | #include "dm-uevent.h" |
1da177e4 LT |
10 | |
11 | #include <linux/init.h> | |
12 | #include <linux/module.h> | |
48c9c27b | 13 | #include <linux/mutex.h> |
1da177e4 LT |
14 | #include <linux/moduleparam.h> |
15 | #include <linux/blkpg.h> | |
16 | #include <linux/bio.h> | |
17 | #include <linux/buffer_head.h> | |
18 | #include <linux/mempool.h> | |
19 | #include <linux/slab.h> | |
20 | #include <linux/idr.h> | |
3ac51e74 | 21 | #include <linux/hdreg.h> |
55782138 LZ |
22 | |
23 | #include <trace/events/block.h> | |
1da177e4 | 24 | |
72d94861 AK |
25 | #define DM_MSG_PREFIX "core" |
26 | ||
60935eb2 MB |
27 | /* |
28 | * Cookies are numeric values sent with CHANGE and REMOVE | |
29 | * uevents while resuming, removing or renaming the device. | |
30 | */ | |
31 | #define DM_COOKIE_ENV_VAR_NAME "DM_COOKIE" | |
32 | #define DM_COOKIE_LENGTH 24 | |
33 | ||
1da177e4 LT |
34 | static const char *_name = DM_NAME; |
35 | ||
36 | static unsigned int major = 0; | |
37 | static unsigned int _major = 0; | |
38 | ||
f32c10b0 | 39 | static DEFINE_SPINLOCK(_minor_lock); |
1da177e4 | 40 | /* |
8fbf26ad | 41 | * For bio-based dm. |
1da177e4 LT |
42 | * One of these is allocated per bio. |
43 | */ | |
44 | struct dm_io { | |
45 | struct mapped_device *md; | |
46 | int error; | |
1da177e4 | 47 | atomic_t io_count; |
6ae2fa67 | 48 | struct bio *bio; |
3eaf840e | 49 | unsigned long start_time; |
1da177e4 LT |
50 | }; |
51 | ||
52 | /* | |
8fbf26ad | 53 | * For bio-based dm. |
1da177e4 LT |
54 | * One of these is allocated per target within a bio. Hopefully |
55 | * this will be simplified out one day. | |
56 | */ | |
028867ac | 57 | struct dm_target_io { |
1da177e4 LT |
58 | struct dm_io *io; |
59 | struct dm_target *ti; | |
60 | union map_info info; | |
61 | }; | |
62 | ||
8fbf26ad KU |
63 | /* |
64 | * For request-based dm. | |
65 | * One of these is allocated per request. | |
66 | */ | |
67 | struct dm_rq_target_io { | |
68 | struct mapped_device *md; | |
69 | struct dm_target *ti; | |
70 | struct request *orig, clone; | |
71 | int error; | |
72 | union map_info info; | |
73 | }; | |
74 | ||
75 | /* | |
76 | * For request-based dm. | |
77 | * One of these is allocated per bio. | |
78 | */ | |
79 | struct dm_rq_clone_bio_info { | |
80 | struct bio *orig; | |
81 | struct request *rq; | |
82 | }; | |
83 | ||
1da177e4 LT |
84 | union map_info *dm_get_mapinfo(struct bio *bio) |
85 | { | |
17b2f66f | 86 | if (bio && bio->bi_private) |
028867ac | 87 | return &((struct dm_target_io *)bio->bi_private)->info; |
17b2f66f | 88 | return NULL; |
1da177e4 LT |
89 | } |
90 | ||
ba61fdd1 JM |
91 | #define MINOR_ALLOCED ((void *)-1) |
92 | ||
1da177e4 LT |
93 | /* |
94 | * Bits for the md->flags field. | |
95 | */ | |
1eb787ec | 96 | #define DMF_BLOCK_IO_FOR_SUSPEND 0 |
1da177e4 | 97 | #define DMF_SUSPENDED 1 |
aa8d7c2f | 98 | #define DMF_FROZEN 2 |
fba9f90e | 99 | #define DMF_FREEING 3 |
5c6bd75d | 100 | #define DMF_DELETING 4 |
2e93ccc1 | 101 | #define DMF_NOFLUSH_SUSPENDING 5 |
1eb787ec | 102 | #define DMF_QUEUE_IO_TO_THREAD 6 |
1da177e4 | 103 | |
304f3f6a MB |
104 | /* |
105 | * Work processed by per-device workqueue. | |
106 | */ | |
1da177e4 | 107 | struct mapped_device { |
2ca3310e | 108 | struct rw_semaphore io_lock; |
e61290a4 | 109 | struct mutex suspend_lock; |
1da177e4 LT |
110 | rwlock_t map_lock; |
111 | atomic_t holders; | |
5c6bd75d | 112 | atomic_t open_count; |
1da177e4 LT |
113 | |
114 | unsigned long flags; | |
115 | ||
165125e1 | 116 | struct request_queue *queue; |
1da177e4 | 117 | struct gendisk *disk; |
7e51f257 | 118 | char name[16]; |
1da177e4 LT |
119 | |
120 | void *interface_ptr; | |
121 | ||
122 | /* | |
123 | * A list of ios that arrived while we were suspended. | |
124 | */ | |
125 | atomic_t pending; | |
126 | wait_queue_head_t wait; | |
53d5914f | 127 | struct work_struct work; |
74859364 | 128 | struct bio_list deferred; |
022c2611 | 129 | spinlock_t deferred_lock; |
1da177e4 | 130 | |
af7e466a MP |
131 | /* |
132 | * An error from the barrier request currently being processed. | |
133 | */ | |
134 | int barrier_error; | |
135 | ||
304f3f6a MB |
136 | /* |
137 | * Processing queue (flush/barriers) | |
138 | */ | |
139 | struct workqueue_struct *wq; | |
140 | ||
1da177e4 LT |
141 | /* |
142 | * The current mapping. | |
143 | */ | |
144 | struct dm_table *map; | |
145 | ||
146 | /* | |
147 | * io objects are allocated from here. | |
148 | */ | |
149 | mempool_t *io_pool; | |
150 | mempool_t *tio_pool; | |
151 | ||
9faf400f SB |
152 | struct bio_set *bs; |
153 | ||
1da177e4 LT |
154 | /* |
155 | * Event handling. | |
156 | */ | |
157 | atomic_t event_nr; | |
158 | wait_queue_head_t eventq; | |
7a8c3d3b MA |
159 | atomic_t uevent_seq; |
160 | struct list_head uevent_list; | |
161 | spinlock_t uevent_lock; /* Protect access to uevent_list */ | |
1da177e4 LT |
162 | |
163 | /* | |
164 | * freeze/thaw support require holding onto a super block | |
165 | */ | |
166 | struct super_block *frozen_sb; | |
db8fef4f | 167 | struct block_device *bdev; |
3ac51e74 DW |
168 | |
169 | /* forced geometry settings */ | |
170 | struct hd_geometry geometry; | |
784aae73 MB |
171 | |
172 | /* sysfs handle */ | |
173 | struct kobject kobj; | |
52b1fd5a MP |
174 | |
175 | /* zero-length barrier that will be cloned and submitted to targets */ | |
176 | struct bio barrier_bio; | |
1da177e4 LT |
177 | }; |
178 | ||
179 | #define MIN_IOS 256 | |
e18b890b CL |
180 | static struct kmem_cache *_io_cache; |
181 | static struct kmem_cache *_tio_cache; | |
8fbf26ad KU |
182 | static struct kmem_cache *_rq_tio_cache; |
183 | static struct kmem_cache *_rq_bio_info_cache; | |
1da177e4 | 184 | |
1da177e4 LT |
185 | static int __init local_init(void) |
186 | { | |
51157b4a | 187 | int r = -ENOMEM; |
1da177e4 | 188 | |
1da177e4 | 189 | /* allocate a slab for the dm_ios */ |
028867ac | 190 | _io_cache = KMEM_CACHE(dm_io, 0); |
1da177e4 | 191 | if (!_io_cache) |
51157b4a | 192 | return r; |
1da177e4 LT |
193 | |
194 | /* allocate a slab for the target ios */ | |
028867ac | 195 | _tio_cache = KMEM_CACHE(dm_target_io, 0); |
51157b4a KU |
196 | if (!_tio_cache) |
197 | goto out_free_io_cache; | |
1da177e4 | 198 | |
8fbf26ad KU |
199 | _rq_tio_cache = KMEM_CACHE(dm_rq_target_io, 0); |
200 | if (!_rq_tio_cache) | |
201 | goto out_free_tio_cache; | |
202 | ||
203 | _rq_bio_info_cache = KMEM_CACHE(dm_rq_clone_bio_info, 0); | |
204 | if (!_rq_bio_info_cache) | |
205 | goto out_free_rq_tio_cache; | |
206 | ||
51e5b2bd | 207 | r = dm_uevent_init(); |
51157b4a | 208 | if (r) |
8fbf26ad | 209 | goto out_free_rq_bio_info_cache; |
51e5b2bd | 210 | |
1da177e4 LT |
211 | _major = major; |
212 | r = register_blkdev(_major, _name); | |
51157b4a KU |
213 | if (r < 0) |
214 | goto out_uevent_exit; | |
1da177e4 LT |
215 | |
216 | if (!_major) | |
217 | _major = r; | |
218 | ||
219 | return 0; | |
51157b4a KU |
220 | |
221 | out_uevent_exit: | |
222 | dm_uevent_exit(); | |
8fbf26ad KU |
223 | out_free_rq_bio_info_cache: |
224 | kmem_cache_destroy(_rq_bio_info_cache); | |
225 | out_free_rq_tio_cache: | |
226 | kmem_cache_destroy(_rq_tio_cache); | |
51157b4a KU |
227 | out_free_tio_cache: |
228 | kmem_cache_destroy(_tio_cache); | |
229 | out_free_io_cache: | |
230 | kmem_cache_destroy(_io_cache); | |
231 | ||
232 | return r; | |
1da177e4 LT |
233 | } |
234 | ||
235 | static void local_exit(void) | |
236 | { | |
8fbf26ad KU |
237 | kmem_cache_destroy(_rq_bio_info_cache); |
238 | kmem_cache_destroy(_rq_tio_cache); | |
1da177e4 LT |
239 | kmem_cache_destroy(_tio_cache); |
240 | kmem_cache_destroy(_io_cache); | |
00d59405 | 241 | unregister_blkdev(_major, _name); |
51e5b2bd | 242 | dm_uevent_exit(); |
1da177e4 LT |
243 | |
244 | _major = 0; | |
245 | ||
246 | DMINFO("cleaned up"); | |
247 | } | |
248 | ||
b9249e55 | 249 | static int (*_inits[])(void) __initdata = { |
1da177e4 LT |
250 | local_init, |
251 | dm_target_init, | |
252 | dm_linear_init, | |
253 | dm_stripe_init, | |
945fa4d2 | 254 | dm_kcopyd_init, |
1da177e4 LT |
255 | dm_interface_init, |
256 | }; | |
257 | ||
b9249e55 | 258 | static void (*_exits[])(void) = { |
1da177e4 LT |
259 | local_exit, |
260 | dm_target_exit, | |
261 | dm_linear_exit, | |
262 | dm_stripe_exit, | |
945fa4d2 | 263 | dm_kcopyd_exit, |
1da177e4 LT |
264 | dm_interface_exit, |
265 | }; | |
266 | ||
267 | static int __init dm_init(void) | |
268 | { | |
269 | const int count = ARRAY_SIZE(_inits); | |
270 | ||
271 | int r, i; | |
272 | ||
273 | for (i = 0; i < count; i++) { | |
274 | r = _inits[i](); | |
275 | if (r) | |
276 | goto bad; | |
277 | } | |
278 | ||
279 | return 0; | |
280 | ||
281 | bad: | |
282 | while (i--) | |
283 | _exits[i](); | |
284 | ||
285 | return r; | |
286 | } | |
287 | ||
288 | static void __exit dm_exit(void) | |
289 | { | |
290 | int i = ARRAY_SIZE(_exits); | |
291 | ||
292 | while (i--) | |
293 | _exits[i](); | |
294 | } | |
295 | ||
296 | /* | |
297 | * Block device functions | |
298 | */ | |
fe5f9f2c | 299 | static int dm_blk_open(struct block_device *bdev, fmode_t mode) |
1da177e4 LT |
300 | { |
301 | struct mapped_device *md; | |
302 | ||
fba9f90e JM |
303 | spin_lock(&_minor_lock); |
304 | ||
fe5f9f2c | 305 | md = bdev->bd_disk->private_data; |
fba9f90e JM |
306 | if (!md) |
307 | goto out; | |
308 | ||
5c6bd75d AK |
309 | if (test_bit(DMF_FREEING, &md->flags) || |
310 | test_bit(DMF_DELETING, &md->flags)) { | |
fba9f90e JM |
311 | md = NULL; |
312 | goto out; | |
313 | } | |
314 | ||
1da177e4 | 315 | dm_get(md); |
5c6bd75d | 316 | atomic_inc(&md->open_count); |
fba9f90e JM |
317 | |
318 | out: | |
319 | spin_unlock(&_minor_lock); | |
320 | ||
321 | return md ? 0 : -ENXIO; | |
1da177e4 LT |
322 | } |
323 | ||
fe5f9f2c | 324 | static int dm_blk_close(struct gendisk *disk, fmode_t mode) |
1da177e4 | 325 | { |
fe5f9f2c | 326 | struct mapped_device *md = disk->private_data; |
5c6bd75d | 327 | atomic_dec(&md->open_count); |
1da177e4 LT |
328 | dm_put(md); |
329 | return 0; | |
330 | } | |
331 | ||
5c6bd75d AK |
332 | int dm_open_count(struct mapped_device *md) |
333 | { | |
334 | return atomic_read(&md->open_count); | |
335 | } | |
336 | ||
337 | /* | |
338 | * Guarantees nothing is using the device before it's deleted. | |
339 | */ | |
340 | int dm_lock_for_deletion(struct mapped_device *md) | |
341 | { | |
342 | int r = 0; | |
343 | ||
344 | spin_lock(&_minor_lock); | |
345 | ||
346 | if (dm_open_count(md)) | |
347 | r = -EBUSY; | |
348 | else | |
349 | set_bit(DMF_DELETING, &md->flags); | |
350 | ||
351 | spin_unlock(&_minor_lock); | |
352 | ||
353 | return r; | |
354 | } | |
355 | ||
3ac51e74 DW |
356 | static int dm_blk_getgeo(struct block_device *bdev, struct hd_geometry *geo) |
357 | { | |
358 | struct mapped_device *md = bdev->bd_disk->private_data; | |
359 | ||
360 | return dm_get_geometry(md, geo); | |
361 | } | |
362 | ||
fe5f9f2c | 363 | static int dm_blk_ioctl(struct block_device *bdev, fmode_t mode, |
aa129a22 MB |
364 | unsigned int cmd, unsigned long arg) |
365 | { | |
fe5f9f2c AV |
366 | struct mapped_device *md = bdev->bd_disk->private_data; |
367 | struct dm_table *map = dm_get_table(md); | |
aa129a22 MB |
368 | struct dm_target *tgt; |
369 | int r = -ENOTTY; | |
370 | ||
aa129a22 MB |
371 | if (!map || !dm_table_get_size(map)) |
372 | goto out; | |
373 | ||
374 | /* We only support devices that have a single target */ | |
375 | if (dm_table_get_num_targets(map) != 1) | |
376 | goto out; | |
377 | ||
378 | tgt = dm_table_get_target(map, 0); | |
379 | ||
380 | if (dm_suspended(md)) { | |
381 | r = -EAGAIN; | |
382 | goto out; | |
383 | } | |
384 | ||
385 | if (tgt->type->ioctl) | |
647b3d00 | 386 | r = tgt->type->ioctl(tgt, cmd, arg); |
aa129a22 MB |
387 | |
388 | out: | |
389 | dm_table_put(map); | |
390 | ||
aa129a22 MB |
391 | return r; |
392 | } | |
393 | ||
028867ac | 394 | static struct dm_io *alloc_io(struct mapped_device *md) |
1da177e4 LT |
395 | { |
396 | return mempool_alloc(md->io_pool, GFP_NOIO); | |
397 | } | |
398 | ||
028867ac | 399 | static void free_io(struct mapped_device *md, struct dm_io *io) |
1da177e4 LT |
400 | { |
401 | mempool_free(io, md->io_pool); | |
402 | } | |
403 | ||
028867ac | 404 | static void free_tio(struct mapped_device *md, struct dm_target_io *tio) |
1da177e4 LT |
405 | { |
406 | mempool_free(tio, md->tio_pool); | |
407 | } | |
408 | ||
3eaf840e JNN |
409 | static void start_io_acct(struct dm_io *io) |
410 | { | |
411 | struct mapped_device *md = io->md; | |
c9959059 | 412 | int cpu; |
3eaf840e JNN |
413 | |
414 | io->start_time = jiffies; | |
415 | ||
074a7aca TH |
416 | cpu = part_stat_lock(); |
417 | part_round_stats(cpu, &dm_disk(md)->part0); | |
418 | part_stat_unlock(); | |
419 | dm_disk(md)->part0.in_flight = atomic_inc_return(&md->pending); | |
3eaf840e JNN |
420 | } |
421 | ||
d221d2e7 | 422 | static void end_io_acct(struct dm_io *io) |
3eaf840e JNN |
423 | { |
424 | struct mapped_device *md = io->md; | |
425 | struct bio *bio = io->bio; | |
426 | unsigned long duration = jiffies - io->start_time; | |
c9959059 | 427 | int pending, cpu; |
3eaf840e JNN |
428 | int rw = bio_data_dir(bio); |
429 | ||
074a7aca TH |
430 | cpu = part_stat_lock(); |
431 | part_round_stats(cpu, &dm_disk(md)->part0); | |
432 | part_stat_add(cpu, &dm_disk(md)->part0, ticks[rw], duration); | |
433 | part_stat_unlock(); | |
3eaf840e | 434 | |
af7e466a MP |
435 | /* |
436 | * After this is decremented the bio must not be touched if it is | |
437 | * a barrier. | |
438 | */ | |
074a7aca TH |
439 | dm_disk(md)->part0.in_flight = pending = |
440 | atomic_dec_return(&md->pending); | |
3eaf840e | 441 | |
d221d2e7 MP |
442 | /* nudge anyone waiting on suspend queue */ |
443 | if (!pending) | |
444 | wake_up(&md->wait); | |
3eaf840e JNN |
445 | } |
446 | ||
1da177e4 LT |
447 | /* |
448 | * Add the bio to the list of deferred io. | |
449 | */ | |
92c63902 | 450 | static void queue_io(struct mapped_device *md, struct bio *bio) |
1da177e4 | 451 | { |
2ca3310e | 452 | down_write(&md->io_lock); |
1da177e4 | 453 | |
022c2611 | 454 | spin_lock_irq(&md->deferred_lock); |
1da177e4 | 455 | bio_list_add(&md->deferred, bio); |
022c2611 | 456 | spin_unlock_irq(&md->deferred_lock); |
1da177e4 | 457 | |
92c63902 MP |
458 | if (!test_and_set_bit(DMF_QUEUE_IO_TO_THREAD, &md->flags)) |
459 | queue_work(md->wq, &md->work); | |
460 | ||
2ca3310e | 461 | up_write(&md->io_lock); |
1da177e4 LT |
462 | } |
463 | ||
464 | /* | |
465 | * Everyone (including functions in this file), should use this | |
466 | * function to access the md->map field, and make sure they call | |
467 | * dm_table_put() when finished. | |
468 | */ | |
469 | struct dm_table *dm_get_table(struct mapped_device *md) | |
470 | { | |
471 | struct dm_table *t; | |
472 | ||
473 | read_lock(&md->map_lock); | |
474 | t = md->map; | |
475 | if (t) | |
476 | dm_table_get(t); | |
477 | read_unlock(&md->map_lock); | |
478 | ||
479 | return t; | |
480 | } | |
481 | ||
3ac51e74 DW |
482 | /* |
483 | * Get the geometry associated with a dm device | |
484 | */ | |
485 | int dm_get_geometry(struct mapped_device *md, struct hd_geometry *geo) | |
486 | { | |
487 | *geo = md->geometry; | |
488 | ||
489 | return 0; | |
490 | } | |
491 | ||
492 | /* | |
493 | * Set the geometry of a device. | |
494 | */ | |
495 | int dm_set_geometry(struct mapped_device *md, struct hd_geometry *geo) | |
496 | { | |
497 | sector_t sz = (sector_t)geo->cylinders * geo->heads * geo->sectors; | |
498 | ||
499 | if (geo->start > sz) { | |
500 | DMWARN("Start sector is beyond the geometry limits."); | |
501 | return -EINVAL; | |
502 | } | |
503 | ||
504 | md->geometry = *geo; | |
505 | ||
506 | return 0; | |
507 | } | |
508 | ||
1da177e4 LT |
509 | /*----------------------------------------------------------------- |
510 | * CRUD START: | |
511 | * A more elegant soln is in the works that uses the queue | |
512 | * merge fn, unfortunately there are a couple of changes to | |
513 | * the block layer that I want to make for this. So in the | |
514 | * interests of getting something for people to use I give | |
515 | * you this clearly demarcated crap. | |
516 | *---------------------------------------------------------------*/ | |
517 | ||
2e93ccc1 KU |
518 | static int __noflush_suspending(struct mapped_device *md) |
519 | { | |
520 | return test_bit(DMF_NOFLUSH_SUSPENDING, &md->flags); | |
521 | } | |
522 | ||
1da177e4 LT |
523 | /* |
524 | * Decrements the number of outstanding ios that a bio has been | |
525 | * cloned into, completing the original io if necc. | |
526 | */ | |
858119e1 | 527 | static void dec_pending(struct dm_io *io, int error) |
1da177e4 | 528 | { |
2e93ccc1 | 529 | unsigned long flags; |
b35f8caa MB |
530 | int io_error; |
531 | struct bio *bio; | |
532 | struct mapped_device *md = io->md; | |
2e93ccc1 KU |
533 | |
534 | /* Push-back supersedes any I/O errors */ | |
b35f8caa | 535 | if (error && !(io->error > 0 && __noflush_suspending(md))) |
1da177e4 LT |
536 | io->error = error; |
537 | ||
538 | if (atomic_dec_and_test(&io->io_count)) { | |
2e93ccc1 KU |
539 | if (io->error == DM_ENDIO_REQUEUE) { |
540 | /* | |
541 | * Target requested pushing back the I/O. | |
2e93ccc1 | 542 | */ |
022c2611 | 543 | spin_lock_irqsave(&md->deferred_lock, flags); |
2761e95f MP |
544 | if (__noflush_suspending(md)) { |
545 | if (!bio_barrier(io->bio)) | |
546 | bio_list_add_head(&md->deferred, | |
547 | io->bio); | |
548 | } else | |
2e93ccc1 KU |
549 | /* noflush suspend was interrupted. */ |
550 | io->error = -EIO; | |
022c2611 | 551 | spin_unlock_irqrestore(&md->deferred_lock, flags); |
2e93ccc1 KU |
552 | } |
553 | ||
b35f8caa MB |
554 | io_error = io->error; |
555 | bio = io->bio; | |
2e93ccc1 | 556 | |
af7e466a MP |
557 | if (bio_barrier(bio)) { |
558 | /* | |
559 | * There can be just one barrier request so we use | |
560 | * a per-device variable for error reporting. | |
561 | * Note that you can't touch the bio after end_io_acct | |
562 | */ | |
fdb9572b | 563 | if (!md->barrier_error && io_error != -EOPNOTSUPP) |
5aa2781d | 564 | md->barrier_error = io_error; |
af7e466a MP |
565 | end_io_acct(io); |
566 | } else { | |
567 | end_io_acct(io); | |
b35f8caa | 568 | |
af7e466a MP |
569 | if (io_error != DM_ENDIO_REQUEUE) { |
570 | trace_block_bio_complete(md->queue, bio); | |
2056a782 | 571 | |
af7e466a MP |
572 | bio_endio(bio, io_error); |
573 | } | |
b35f8caa | 574 | } |
af7e466a MP |
575 | |
576 | free_io(md, io); | |
1da177e4 LT |
577 | } |
578 | } | |
579 | ||
6712ecf8 | 580 | static void clone_endio(struct bio *bio, int error) |
1da177e4 LT |
581 | { |
582 | int r = 0; | |
028867ac | 583 | struct dm_target_io *tio = bio->bi_private; |
b35f8caa | 584 | struct dm_io *io = tio->io; |
9faf400f | 585 | struct mapped_device *md = tio->io->md; |
1da177e4 LT |
586 | dm_endio_fn endio = tio->ti->type->end_io; |
587 | ||
1da177e4 LT |
588 | if (!bio_flagged(bio, BIO_UPTODATE) && !error) |
589 | error = -EIO; | |
590 | ||
591 | if (endio) { | |
592 | r = endio(tio->ti, bio, error, &tio->info); | |
2e93ccc1 KU |
593 | if (r < 0 || r == DM_ENDIO_REQUEUE) |
594 | /* | |
595 | * error and requeue request are handled | |
596 | * in dec_pending(). | |
597 | */ | |
1da177e4 | 598 | error = r; |
45cbcd79 KU |
599 | else if (r == DM_ENDIO_INCOMPLETE) |
600 | /* The target will handle the io */ | |
6712ecf8 | 601 | return; |
45cbcd79 KU |
602 | else if (r) { |
603 | DMWARN("unimplemented target endio return value: %d", r); | |
604 | BUG(); | |
605 | } | |
1da177e4 LT |
606 | } |
607 | ||
9faf400f SB |
608 | /* |
609 | * Store md for cleanup instead of tio which is about to get freed. | |
610 | */ | |
611 | bio->bi_private = md->bs; | |
612 | ||
9faf400f | 613 | free_tio(md, tio); |
b35f8caa MB |
614 | bio_put(bio); |
615 | dec_pending(io, error); | |
1da177e4 LT |
616 | } |
617 | ||
618 | static sector_t max_io_len(struct mapped_device *md, | |
619 | sector_t sector, struct dm_target *ti) | |
620 | { | |
621 | sector_t offset = sector - ti->begin; | |
622 | sector_t len = ti->len - offset; | |
623 | ||
624 | /* | |
625 | * Does the target need to split even further ? | |
626 | */ | |
627 | if (ti->split_io) { | |
628 | sector_t boundary; | |
629 | boundary = ((offset + ti->split_io) & ~(ti->split_io - 1)) | |
630 | - offset; | |
631 | if (len > boundary) | |
632 | len = boundary; | |
633 | } | |
634 | ||
635 | return len; | |
636 | } | |
637 | ||
638 | static void __map_bio(struct dm_target *ti, struct bio *clone, | |
028867ac | 639 | struct dm_target_io *tio) |
1da177e4 LT |
640 | { |
641 | int r; | |
2056a782 | 642 | sector_t sector; |
9faf400f | 643 | struct mapped_device *md; |
1da177e4 | 644 | |
1da177e4 LT |
645 | clone->bi_end_io = clone_endio; |
646 | clone->bi_private = tio; | |
647 | ||
648 | /* | |
649 | * Map the clone. If r == 0 we don't need to do | |
650 | * anything, the target has assumed ownership of | |
651 | * this io. | |
652 | */ | |
653 | atomic_inc(&tio->io->io_count); | |
2056a782 | 654 | sector = clone->bi_sector; |
1da177e4 | 655 | r = ti->type->map(ti, clone, &tio->info); |
45cbcd79 | 656 | if (r == DM_MAPIO_REMAPPED) { |
1da177e4 | 657 | /* the bio has been remapped so dispatch it */ |
2056a782 | 658 | |
5f3ea37c | 659 | trace_block_remap(bdev_get_queue(clone->bi_bdev), clone, |
22a7c31a | 660 | tio->io->bio->bi_bdev->bd_dev, sector); |
2056a782 | 661 | |
1da177e4 | 662 | generic_make_request(clone); |
2e93ccc1 KU |
663 | } else if (r < 0 || r == DM_MAPIO_REQUEUE) { |
664 | /* error the io and bail out, or requeue it if needed */ | |
9faf400f SB |
665 | md = tio->io->md; |
666 | dec_pending(tio->io, r); | |
667 | /* | |
668 | * Store bio_set for cleanup. | |
669 | */ | |
670 | clone->bi_private = md->bs; | |
1da177e4 | 671 | bio_put(clone); |
9faf400f | 672 | free_tio(md, tio); |
45cbcd79 KU |
673 | } else if (r) { |
674 | DMWARN("unimplemented target map return value: %d", r); | |
675 | BUG(); | |
1da177e4 LT |
676 | } |
677 | } | |
678 | ||
679 | struct clone_info { | |
680 | struct mapped_device *md; | |
681 | struct dm_table *map; | |
682 | struct bio *bio; | |
683 | struct dm_io *io; | |
684 | sector_t sector; | |
685 | sector_t sector_count; | |
686 | unsigned short idx; | |
687 | }; | |
688 | ||
3676347a PO |
689 | static void dm_bio_destructor(struct bio *bio) |
690 | { | |
9faf400f SB |
691 | struct bio_set *bs = bio->bi_private; |
692 | ||
693 | bio_free(bio, bs); | |
3676347a PO |
694 | } |
695 | ||
1da177e4 LT |
696 | /* |
697 | * Creates a little bio that is just does part of a bvec. | |
698 | */ | |
699 | static struct bio *split_bvec(struct bio *bio, sector_t sector, | |
700 | unsigned short idx, unsigned int offset, | |
9faf400f | 701 | unsigned int len, struct bio_set *bs) |
1da177e4 LT |
702 | { |
703 | struct bio *clone; | |
704 | struct bio_vec *bv = bio->bi_io_vec + idx; | |
705 | ||
9faf400f | 706 | clone = bio_alloc_bioset(GFP_NOIO, 1, bs); |
3676347a | 707 | clone->bi_destructor = dm_bio_destructor; |
1da177e4 LT |
708 | *clone->bi_io_vec = *bv; |
709 | ||
710 | clone->bi_sector = sector; | |
711 | clone->bi_bdev = bio->bi_bdev; | |
af7e466a | 712 | clone->bi_rw = bio->bi_rw & ~(1 << BIO_RW_BARRIER); |
1da177e4 LT |
713 | clone->bi_vcnt = 1; |
714 | clone->bi_size = to_bytes(len); | |
715 | clone->bi_io_vec->bv_offset = offset; | |
716 | clone->bi_io_vec->bv_len = clone->bi_size; | |
f3e1d26e | 717 | clone->bi_flags |= 1 << BIO_CLONED; |
1da177e4 | 718 | |
9c47008d MP |
719 | if (bio_integrity(bio)) { |
720 | bio_integrity_clone(clone, bio, GFP_NOIO); | |
721 | bio_integrity_trim(clone, | |
722 | bio_sector_offset(bio, idx, offset), len); | |
723 | } | |
724 | ||
1da177e4 LT |
725 | return clone; |
726 | } | |
727 | ||
728 | /* | |
729 | * Creates a bio that consists of range of complete bvecs. | |
730 | */ | |
731 | static struct bio *clone_bio(struct bio *bio, sector_t sector, | |
732 | unsigned short idx, unsigned short bv_count, | |
9faf400f | 733 | unsigned int len, struct bio_set *bs) |
1da177e4 LT |
734 | { |
735 | struct bio *clone; | |
736 | ||
9faf400f SB |
737 | clone = bio_alloc_bioset(GFP_NOIO, bio->bi_max_vecs, bs); |
738 | __bio_clone(clone, bio); | |
af7e466a | 739 | clone->bi_rw &= ~(1 << BIO_RW_BARRIER); |
9faf400f | 740 | clone->bi_destructor = dm_bio_destructor; |
1da177e4 LT |
741 | clone->bi_sector = sector; |
742 | clone->bi_idx = idx; | |
743 | clone->bi_vcnt = idx + bv_count; | |
744 | clone->bi_size = to_bytes(len); | |
745 | clone->bi_flags &= ~(1 << BIO_SEG_VALID); | |
746 | ||
9c47008d MP |
747 | if (bio_integrity(bio)) { |
748 | bio_integrity_clone(clone, bio, GFP_NOIO); | |
749 | ||
750 | if (idx != bio->bi_idx || clone->bi_size < bio->bi_size) | |
751 | bio_integrity_trim(clone, | |
752 | bio_sector_offset(bio, idx, 0), len); | |
753 | } | |
754 | ||
1da177e4 LT |
755 | return clone; |
756 | } | |
757 | ||
9015df24 AK |
758 | static struct dm_target_io *alloc_tio(struct clone_info *ci, |
759 | struct dm_target *ti) | |
f9ab94ce | 760 | { |
9015df24 | 761 | struct dm_target_io *tio = mempool_alloc(ci->md->tio_pool, GFP_NOIO); |
f9ab94ce MP |
762 | |
763 | tio->io = ci->io; | |
764 | tio->ti = ti; | |
f9ab94ce | 765 | memset(&tio->info, 0, sizeof(tio->info)); |
9015df24 AK |
766 | |
767 | return tio; | |
768 | } | |
769 | ||
770 | static void __flush_target(struct clone_info *ci, struct dm_target *ti, | |
771 | unsigned flush_nr) | |
772 | { | |
773 | struct dm_target_io *tio = alloc_tio(ci, ti); | |
774 | struct bio *clone; | |
775 | ||
f9ab94ce MP |
776 | tio->info.flush_request = flush_nr; |
777 | ||
778 | clone = bio_alloc_bioset(GFP_NOIO, 0, ci->md->bs); | |
779 | __bio_clone(clone, ci->bio); | |
780 | clone->bi_destructor = dm_bio_destructor; | |
781 | ||
782 | __map_bio(ti, clone, tio); | |
783 | } | |
784 | ||
785 | static int __clone_and_map_empty_barrier(struct clone_info *ci) | |
786 | { | |
787 | unsigned target_nr = 0, flush_nr; | |
788 | struct dm_target *ti; | |
789 | ||
790 | while ((ti = dm_table_get_target(ci->map, target_nr++))) | |
791 | for (flush_nr = 0; flush_nr < ti->num_flush_requests; | |
792 | flush_nr++) | |
793 | __flush_target(ci, ti, flush_nr); | |
794 | ||
795 | ci->sector_count = 0; | |
796 | ||
797 | return 0; | |
798 | } | |
799 | ||
512875bd | 800 | static int __clone_and_map(struct clone_info *ci) |
1da177e4 LT |
801 | { |
802 | struct bio *clone, *bio = ci->bio; | |
512875bd JN |
803 | struct dm_target *ti; |
804 | sector_t len = 0, max; | |
028867ac | 805 | struct dm_target_io *tio; |
1da177e4 | 806 | |
f9ab94ce MP |
807 | if (unlikely(bio_empty_barrier(bio))) |
808 | return __clone_and_map_empty_barrier(ci); | |
809 | ||
512875bd JN |
810 | ti = dm_table_find_target(ci->map, ci->sector); |
811 | if (!dm_target_is_valid(ti)) | |
812 | return -EIO; | |
813 | ||
814 | max = max_io_len(ci->md, ci->sector, ti); | |
815 | ||
1da177e4 LT |
816 | /* |
817 | * Allocate a target io object. | |
818 | */ | |
9015df24 | 819 | tio = alloc_tio(ci, ti); |
1da177e4 LT |
820 | |
821 | if (ci->sector_count <= max) { | |
822 | /* | |
823 | * Optimise for the simple case where we can do all of | |
824 | * the remaining io with a single clone. | |
825 | */ | |
826 | clone = clone_bio(bio, ci->sector, ci->idx, | |
9faf400f SB |
827 | bio->bi_vcnt - ci->idx, ci->sector_count, |
828 | ci->md->bs); | |
1da177e4 LT |
829 | __map_bio(ti, clone, tio); |
830 | ci->sector_count = 0; | |
831 | ||
832 | } else if (to_sector(bio->bi_io_vec[ci->idx].bv_len) <= max) { | |
833 | /* | |
834 | * There are some bvecs that don't span targets. | |
835 | * Do as many of these as possible. | |
836 | */ | |
837 | int i; | |
838 | sector_t remaining = max; | |
839 | sector_t bv_len; | |
840 | ||
841 | for (i = ci->idx; remaining && (i < bio->bi_vcnt); i++) { | |
842 | bv_len = to_sector(bio->bi_io_vec[i].bv_len); | |
843 | ||
844 | if (bv_len > remaining) | |
845 | break; | |
846 | ||
847 | remaining -= bv_len; | |
848 | len += bv_len; | |
849 | } | |
850 | ||
9faf400f SB |
851 | clone = clone_bio(bio, ci->sector, ci->idx, i - ci->idx, len, |
852 | ci->md->bs); | |
1da177e4 LT |
853 | __map_bio(ti, clone, tio); |
854 | ||
855 | ci->sector += len; | |
856 | ci->sector_count -= len; | |
857 | ci->idx = i; | |
858 | ||
859 | } else { | |
860 | /* | |
d2044a94 | 861 | * Handle a bvec that must be split between two or more targets. |
1da177e4 LT |
862 | */ |
863 | struct bio_vec *bv = bio->bi_io_vec + ci->idx; | |
d2044a94 AK |
864 | sector_t remaining = to_sector(bv->bv_len); |
865 | unsigned int offset = 0; | |
1da177e4 | 866 | |
d2044a94 AK |
867 | do { |
868 | if (offset) { | |
869 | ti = dm_table_find_target(ci->map, ci->sector); | |
512875bd JN |
870 | if (!dm_target_is_valid(ti)) |
871 | return -EIO; | |
872 | ||
d2044a94 | 873 | max = max_io_len(ci->md, ci->sector, ti); |
1da177e4 | 874 | |
9015df24 | 875 | tio = alloc_tio(ci, ti); |
d2044a94 AK |
876 | } |
877 | ||
878 | len = min(remaining, max); | |
879 | ||
880 | clone = split_bvec(bio, ci->sector, ci->idx, | |
9faf400f SB |
881 | bv->bv_offset + offset, len, |
882 | ci->md->bs); | |
d2044a94 AK |
883 | |
884 | __map_bio(ti, clone, tio); | |
885 | ||
886 | ci->sector += len; | |
887 | ci->sector_count -= len; | |
888 | offset += to_bytes(len); | |
889 | } while (remaining -= len); | |
1da177e4 | 890 | |
1da177e4 LT |
891 | ci->idx++; |
892 | } | |
512875bd JN |
893 | |
894 | return 0; | |
1da177e4 LT |
895 | } |
896 | ||
897 | /* | |
8a53c28d | 898 | * Split the bio into several clones and submit it to targets. |
1da177e4 | 899 | */ |
f0b9a450 | 900 | static void __split_and_process_bio(struct mapped_device *md, struct bio *bio) |
1da177e4 LT |
901 | { |
902 | struct clone_info ci; | |
512875bd | 903 | int error = 0; |
1da177e4 LT |
904 | |
905 | ci.map = dm_get_table(md); | |
f0b9a450 | 906 | if (unlikely(!ci.map)) { |
af7e466a MP |
907 | if (!bio_barrier(bio)) |
908 | bio_io_error(bio); | |
909 | else | |
5aa2781d MP |
910 | if (!md->barrier_error) |
911 | md->barrier_error = -EIO; | |
f0b9a450 MP |
912 | return; |
913 | } | |
692d0eb9 | 914 | |
1da177e4 LT |
915 | ci.md = md; |
916 | ci.bio = bio; | |
917 | ci.io = alloc_io(md); | |
918 | ci.io->error = 0; | |
919 | atomic_set(&ci.io->io_count, 1); | |
920 | ci.io->bio = bio; | |
921 | ci.io->md = md; | |
922 | ci.sector = bio->bi_sector; | |
923 | ci.sector_count = bio_sectors(bio); | |
f9ab94ce MP |
924 | if (unlikely(bio_empty_barrier(bio))) |
925 | ci.sector_count = 1; | |
1da177e4 LT |
926 | ci.idx = bio->bi_idx; |
927 | ||
3eaf840e | 928 | start_io_acct(ci.io); |
512875bd JN |
929 | while (ci.sector_count && !error) |
930 | error = __clone_and_map(&ci); | |
1da177e4 LT |
931 | |
932 | /* drop the extra reference count */ | |
512875bd | 933 | dec_pending(ci.io, error); |
1da177e4 LT |
934 | dm_table_put(ci.map); |
935 | } | |
936 | /*----------------------------------------------------------------- | |
937 | * CRUD END | |
938 | *---------------------------------------------------------------*/ | |
939 | ||
f6fccb12 MB |
940 | static int dm_merge_bvec(struct request_queue *q, |
941 | struct bvec_merge_data *bvm, | |
942 | struct bio_vec *biovec) | |
943 | { | |
944 | struct mapped_device *md = q->queuedata; | |
945 | struct dm_table *map = dm_get_table(md); | |
946 | struct dm_target *ti; | |
947 | sector_t max_sectors; | |
5037108a | 948 | int max_size = 0; |
f6fccb12 MB |
949 | |
950 | if (unlikely(!map)) | |
5037108a | 951 | goto out; |
f6fccb12 MB |
952 | |
953 | ti = dm_table_find_target(map, bvm->bi_sector); | |
b01cd5ac MP |
954 | if (!dm_target_is_valid(ti)) |
955 | goto out_table; | |
f6fccb12 MB |
956 | |
957 | /* | |
958 | * Find maximum amount of I/O that won't need splitting | |
959 | */ | |
960 | max_sectors = min(max_io_len(md, bvm->bi_sector, ti), | |
961 | (sector_t) BIO_MAX_SECTORS); | |
962 | max_size = (max_sectors << SECTOR_SHIFT) - bvm->bi_size; | |
963 | if (max_size < 0) | |
964 | max_size = 0; | |
965 | ||
966 | /* | |
967 | * merge_bvec_fn() returns number of bytes | |
968 | * it can accept at this offset | |
969 | * max is precomputed maximal io size | |
970 | */ | |
971 | if (max_size && ti->type->merge) | |
972 | max_size = ti->type->merge(ti, bvm, biovec, max_size); | |
8cbeb67a MP |
973 | /* |
974 | * If the target doesn't support merge method and some of the devices | |
975 | * provided their merge_bvec method (we know this by looking at | |
976 | * queue_max_hw_sectors), then we can't allow bios with multiple vector | |
977 | * entries. So always set max_size to 0, and the code below allows | |
978 | * just one page. | |
979 | */ | |
980 | else if (queue_max_hw_sectors(q) <= PAGE_SIZE >> 9) | |
981 | ||
982 | max_size = 0; | |
f6fccb12 | 983 | |
b01cd5ac | 984 | out_table: |
5037108a MP |
985 | dm_table_put(map); |
986 | ||
987 | out: | |
f6fccb12 MB |
988 | /* |
989 | * Always allow an entire first page | |
990 | */ | |
991 | if (max_size <= biovec->bv_len && !(bvm->bi_size >> SECTOR_SHIFT)) | |
992 | max_size = biovec->bv_len; | |
993 | ||
f6fccb12 MB |
994 | return max_size; |
995 | } | |
996 | ||
1da177e4 LT |
997 | /* |
998 | * The request function that just remaps the bio built up by | |
999 | * dm_merge_bvec. | |
1000 | */ | |
165125e1 | 1001 | static int dm_request(struct request_queue *q, struct bio *bio) |
1da177e4 | 1002 | { |
12f03a49 | 1003 | int rw = bio_data_dir(bio); |
1da177e4 | 1004 | struct mapped_device *md = q->queuedata; |
c9959059 | 1005 | int cpu; |
1da177e4 | 1006 | |
2ca3310e | 1007 | down_read(&md->io_lock); |
1da177e4 | 1008 | |
074a7aca TH |
1009 | cpu = part_stat_lock(); |
1010 | part_stat_inc(cpu, &dm_disk(md)->part0, ios[rw]); | |
1011 | part_stat_add(cpu, &dm_disk(md)->part0, sectors[rw], bio_sectors(bio)); | |
1012 | part_stat_unlock(); | |
12f03a49 | 1013 | |
1da177e4 | 1014 | /* |
1eb787ec AK |
1015 | * If we're suspended or the thread is processing barriers |
1016 | * we have to queue this io for later. | |
1da177e4 | 1017 | */ |
af7e466a MP |
1018 | if (unlikely(test_bit(DMF_QUEUE_IO_TO_THREAD, &md->flags)) || |
1019 | unlikely(bio_barrier(bio))) { | |
2ca3310e | 1020 | up_read(&md->io_lock); |
1da177e4 | 1021 | |
54d9a1b4 AK |
1022 | if (unlikely(test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags)) && |
1023 | bio_rw(bio) == READA) { | |
1024 | bio_io_error(bio); | |
1025 | return 0; | |
1026 | } | |
1da177e4 | 1027 | |
92c63902 | 1028 | queue_io(md, bio); |
1da177e4 | 1029 | |
92c63902 | 1030 | return 0; |
1da177e4 LT |
1031 | } |
1032 | ||
f0b9a450 | 1033 | __split_and_process_bio(md, bio); |
2ca3310e | 1034 | up_read(&md->io_lock); |
f0b9a450 | 1035 | return 0; |
1da177e4 LT |
1036 | } |
1037 | ||
165125e1 | 1038 | static void dm_unplug_all(struct request_queue *q) |
1da177e4 LT |
1039 | { |
1040 | struct mapped_device *md = q->queuedata; | |
1041 | struct dm_table *map = dm_get_table(md); | |
1042 | ||
1043 | if (map) { | |
1044 | dm_table_unplug_all(map); | |
1045 | dm_table_put(map); | |
1046 | } | |
1047 | } | |
1048 | ||
1049 | static int dm_any_congested(void *congested_data, int bdi_bits) | |
1050 | { | |
8a57dfc6 CS |
1051 | int r = bdi_bits; |
1052 | struct mapped_device *md = congested_data; | |
1053 | struct dm_table *map; | |
1da177e4 | 1054 | |
1eb787ec | 1055 | if (!test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags)) { |
8a57dfc6 CS |
1056 | map = dm_get_table(md); |
1057 | if (map) { | |
1058 | r = dm_table_any_congested(map, bdi_bits); | |
1059 | dm_table_put(map); | |
1060 | } | |
1061 | } | |
1062 | ||
1da177e4 LT |
1063 | return r; |
1064 | } | |
1065 | ||
1066 | /*----------------------------------------------------------------- | |
1067 | * An IDR is used to keep track of allocated minor numbers. | |
1068 | *---------------------------------------------------------------*/ | |
1da177e4 LT |
1069 | static DEFINE_IDR(_minor_idr); |
1070 | ||
2b06cfff | 1071 | static void free_minor(int minor) |
1da177e4 | 1072 | { |
f32c10b0 | 1073 | spin_lock(&_minor_lock); |
1da177e4 | 1074 | idr_remove(&_minor_idr, minor); |
f32c10b0 | 1075 | spin_unlock(&_minor_lock); |
1da177e4 LT |
1076 | } |
1077 | ||
1078 | /* | |
1079 | * See if the device with a specific minor # is free. | |
1080 | */ | |
cf13ab8e | 1081 | static int specific_minor(int minor) |
1da177e4 LT |
1082 | { |
1083 | int r, m; | |
1084 | ||
1085 | if (minor >= (1 << MINORBITS)) | |
1086 | return -EINVAL; | |
1087 | ||
62f75c2f JM |
1088 | r = idr_pre_get(&_minor_idr, GFP_KERNEL); |
1089 | if (!r) | |
1090 | return -ENOMEM; | |
1091 | ||
f32c10b0 | 1092 | spin_lock(&_minor_lock); |
1da177e4 LT |
1093 | |
1094 | if (idr_find(&_minor_idr, minor)) { | |
1095 | r = -EBUSY; | |
1096 | goto out; | |
1097 | } | |
1098 | ||
ba61fdd1 | 1099 | r = idr_get_new_above(&_minor_idr, MINOR_ALLOCED, minor, &m); |
62f75c2f | 1100 | if (r) |
1da177e4 | 1101 | goto out; |
1da177e4 LT |
1102 | |
1103 | if (m != minor) { | |
1104 | idr_remove(&_minor_idr, m); | |
1105 | r = -EBUSY; | |
1106 | goto out; | |
1107 | } | |
1108 | ||
1109 | out: | |
f32c10b0 | 1110 | spin_unlock(&_minor_lock); |
1da177e4 LT |
1111 | return r; |
1112 | } | |
1113 | ||
cf13ab8e | 1114 | static int next_free_minor(int *minor) |
1da177e4 | 1115 | { |
2b06cfff | 1116 | int r, m; |
1da177e4 | 1117 | |
1da177e4 | 1118 | r = idr_pre_get(&_minor_idr, GFP_KERNEL); |
62f75c2f JM |
1119 | if (!r) |
1120 | return -ENOMEM; | |
1121 | ||
f32c10b0 | 1122 | spin_lock(&_minor_lock); |
1da177e4 | 1123 | |
ba61fdd1 | 1124 | r = idr_get_new(&_minor_idr, MINOR_ALLOCED, &m); |
cf13ab8e | 1125 | if (r) |
1da177e4 | 1126 | goto out; |
1da177e4 LT |
1127 | |
1128 | if (m >= (1 << MINORBITS)) { | |
1129 | idr_remove(&_minor_idr, m); | |
1130 | r = -ENOSPC; | |
1131 | goto out; | |
1132 | } | |
1133 | ||
1134 | *minor = m; | |
1135 | ||
1136 | out: | |
f32c10b0 | 1137 | spin_unlock(&_minor_lock); |
1da177e4 LT |
1138 | return r; |
1139 | } | |
1140 | ||
1141 | static struct block_device_operations dm_blk_dops; | |
1142 | ||
53d5914f MP |
1143 | static void dm_wq_work(struct work_struct *work); |
1144 | ||
1da177e4 LT |
1145 | /* |
1146 | * Allocate and initialise a blank device with a given minor. | |
1147 | */ | |
2b06cfff | 1148 | static struct mapped_device *alloc_dev(int minor) |
1da177e4 LT |
1149 | { |
1150 | int r; | |
cf13ab8e | 1151 | struct mapped_device *md = kzalloc(sizeof(*md), GFP_KERNEL); |
ba61fdd1 | 1152 | void *old_md; |
1da177e4 LT |
1153 | |
1154 | if (!md) { | |
1155 | DMWARN("unable to allocate device, out of memory."); | |
1156 | return NULL; | |
1157 | } | |
1158 | ||
10da4f79 | 1159 | if (!try_module_get(THIS_MODULE)) |
6ed7ade8 | 1160 | goto bad_module_get; |
10da4f79 | 1161 | |
1da177e4 | 1162 | /* get a minor number for the dev */ |
2b06cfff | 1163 | if (minor == DM_ANY_MINOR) |
cf13ab8e | 1164 | r = next_free_minor(&minor); |
2b06cfff | 1165 | else |
cf13ab8e | 1166 | r = specific_minor(minor); |
1da177e4 | 1167 | if (r < 0) |
6ed7ade8 | 1168 | goto bad_minor; |
1da177e4 | 1169 | |
2ca3310e | 1170 | init_rwsem(&md->io_lock); |
e61290a4 | 1171 | mutex_init(&md->suspend_lock); |
022c2611 | 1172 | spin_lock_init(&md->deferred_lock); |
1da177e4 LT |
1173 | rwlock_init(&md->map_lock); |
1174 | atomic_set(&md->holders, 1); | |
5c6bd75d | 1175 | atomic_set(&md->open_count, 0); |
1da177e4 | 1176 | atomic_set(&md->event_nr, 0); |
7a8c3d3b MA |
1177 | atomic_set(&md->uevent_seq, 0); |
1178 | INIT_LIST_HEAD(&md->uevent_list); | |
1179 | spin_lock_init(&md->uevent_lock); | |
1da177e4 LT |
1180 | |
1181 | md->queue = blk_alloc_queue(GFP_KERNEL); | |
1182 | if (!md->queue) | |
6ed7ade8 | 1183 | goto bad_queue; |
1da177e4 LT |
1184 | |
1185 | md->queue->queuedata = md; | |
1186 | md->queue->backing_dev_info.congested_fn = dm_any_congested; | |
1187 | md->queue->backing_dev_info.congested_data = md; | |
1188 | blk_queue_make_request(md->queue, dm_request); | |
99360b4c | 1189 | blk_queue_ordered(md->queue, QUEUE_ORDERED_DRAIN, NULL); |
daef265f | 1190 | blk_queue_bounce_limit(md->queue, BLK_BOUNCE_ANY); |
1da177e4 | 1191 | md->queue->unplug_fn = dm_unplug_all; |
f6fccb12 | 1192 | blk_queue_merge_bvec(md->queue, dm_merge_bvec); |
1da177e4 | 1193 | |
93d2341c | 1194 | md->io_pool = mempool_create_slab_pool(MIN_IOS, _io_cache); |
74859364 | 1195 | if (!md->io_pool) |
6ed7ade8 | 1196 | goto bad_io_pool; |
1da177e4 | 1197 | |
93d2341c | 1198 | md->tio_pool = mempool_create_slab_pool(MIN_IOS, _tio_cache); |
1da177e4 | 1199 | if (!md->tio_pool) |
6ed7ade8 | 1200 | goto bad_tio_pool; |
1da177e4 | 1201 | |
bb799ca0 | 1202 | md->bs = bioset_create(16, 0); |
9faf400f SB |
1203 | if (!md->bs) |
1204 | goto bad_no_bioset; | |
1205 | ||
1da177e4 LT |
1206 | md->disk = alloc_disk(1); |
1207 | if (!md->disk) | |
6ed7ade8 | 1208 | goto bad_disk; |
1da177e4 | 1209 | |
f0b04115 JM |
1210 | atomic_set(&md->pending, 0); |
1211 | init_waitqueue_head(&md->wait); | |
53d5914f | 1212 | INIT_WORK(&md->work, dm_wq_work); |
f0b04115 JM |
1213 | init_waitqueue_head(&md->eventq); |
1214 | ||
1da177e4 LT |
1215 | md->disk->major = _major; |
1216 | md->disk->first_minor = minor; | |
1217 | md->disk->fops = &dm_blk_dops; | |
1218 | md->disk->queue = md->queue; | |
1219 | md->disk->private_data = md; | |
1220 | sprintf(md->disk->disk_name, "dm-%d", minor); | |
1221 | add_disk(md->disk); | |
7e51f257 | 1222 | format_dev_t(md->name, MKDEV(_major, minor)); |
1da177e4 | 1223 | |
304f3f6a MB |
1224 | md->wq = create_singlethread_workqueue("kdmflush"); |
1225 | if (!md->wq) | |
1226 | goto bad_thread; | |
1227 | ||
32a926da MP |
1228 | md->bdev = bdget_disk(md->disk, 0); |
1229 | if (!md->bdev) | |
1230 | goto bad_bdev; | |
1231 | ||
ba61fdd1 | 1232 | /* Populate the mapping, nobody knows we exist yet */ |
f32c10b0 | 1233 | spin_lock(&_minor_lock); |
ba61fdd1 | 1234 | old_md = idr_replace(&_minor_idr, md, minor); |
f32c10b0 | 1235 | spin_unlock(&_minor_lock); |
ba61fdd1 JM |
1236 | |
1237 | BUG_ON(old_md != MINOR_ALLOCED); | |
1238 | ||
1da177e4 LT |
1239 | return md; |
1240 | ||
32a926da MP |
1241 | bad_bdev: |
1242 | destroy_workqueue(md->wq); | |
304f3f6a MB |
1243 | bad_thread: |
1244 | put_disk(md->disk); | |
6ed7ade8 | 1245 | bad_disk: |
9faf400f | 1246 | bioset_free(md->bs); |
6ed7ade8 | 1247 | bad_no_bioset: |
1da177e4 | 1248 | mempool_destroy(md->tio_pool); |
6ed7ade8 | 1249 | bad_tio_pool: |
1da177e4 | 1250 | mempool_destroy(md->io_pool); |
6ed7ade8 | 1251 | bad_io_pool: |
1312f40e | 1252 | blk_cleanup_queue(md->queue); |
6ed7ade8 | 1253 | bad_queue: |
1da177e4 | 1254 | free_minor(minor); |
6ed7ade8 | 1255 | bad_minor: |
10da4f79 | 1256 | module_put(THIS_MODULE); |
6ed7ade8 | 1257 | bad_module_get: |
1da177e4 LT |
1258 | kfree(md); |
1259 | return NULL; | |
1260 | } | |
1261 | ||
ae9da83f JN |
1262 | static void unlock_fs(struct mapped_device *md); |
1263 | ||
1da177e4 LT |
1264 | static void free_dev(struct mapped_device *md) |
1265 | { | |
f331c029 | 1266 | int minor = MINOR(disk_devt(md->disk)); |
63d94e48 | 1267 | |
32a926da MP |
1268 | unlock_fs(md); |
1269 | bdput(md->bdev); | |
304f3f6a | 1270 | destroy_workqueue(md->wq); |
1da177e4 LT |
1271 | mempool_destroy(md->tio_pool); |
1272 | mempool_destroy(md->io_pool); | |
9faf400f | 1273 | bioset_free(md->bs); |
9c47008d | 1274 | blk_integrity_unregister(md->disk); |
1da177e4 | 1275 | del_gendisk(md->disk); |
63d94e48 | 1276 | free_minor(minor); |
fba9f90e JM |
1277 | |
1278 | spin_lock(&_minor_lock); | |
1279 | md->disk->private_data = NULL; | |
1280 | spin_unlock(&_minor_lock); | |
1281 | ||
1da177e4 | 1282 | put_disk(md->disk); |
1312f40e | 1283 | blk_cleanup_queue(md->queue); |
10da4f79 | 1284 | module_put(THIS_MODULE); |
1da177e4 LT |
1285 | kfree(md); |
1286 | } | |
1287 | ||
1288 | /* | |
1289 | * Bind a table to the device. | |
1290 | */ | |
1291 | static void event_callback(void *context) | |
1292 | { | |
7a8c3d3b MA |
1293 | unsigned long flags; |
1294 | LIST_HEAD(uevents); | |
1da177e4 LT |
1295 | struct mapped_device *md = (struct mapped_device *) context; |
1296 | ||
7a8c3d3b MA |
1297 | spin_lock_irqsave(&md->uevent_lock, flags); |
1298 | list_splice_init(&md->uevent_list, &uevents); | |
1299 | spin_unlock_irqrestore(&md->uevent_lock, flags); | |
1300 | ||
ed9e1982 | 1301 | dm_send_uevents(&uevents, &disk_to_dev(md->disk)->kobj); |
7a8c3d3b | 1302 | |
1da177e4 LT |
1303 | atomic_inc(&md->event_nr); |
1304 | wake_up(&md->eventq); | |
1305 | } | |
1306 | ||
4e90188b | 1307 | static void __set_size(struct mapped_device *md, sector_t size) |
1da177e4 | 1308 | { |
4e90188b | 1309 | set_capacity(md->disk, size); |
1da177e4 | 1310 | |
db8fef4f MP |
1311 | mutex_lock(&md->bdev->bd_inode->i_mutex); |
1312 | i_size_write(md->bdev->bd_inode, (loff_t)size << SECTOR_SHIFT); | |
1313 | mutex_unlock(&md->bdev->bd_inode->i_mutex); | |
1da177e4 LT |
1314 | } |
1315 | ||
754c5fc7 MS |
1316 | static int __bind(struct mapped_device *md, struct dm_table *t, |
1317 | struct queue_limits *limits) | |
1da177e4 | 1318 | { |
165125e1 | 1319 | struct request_queue *q = md->queue; |
1da177e4 LT |
1320 | sector_t size; |
1321 | ||
1322 | size = dm_table_get_size(t); | |
3ac51e74 DW |
1323 | |
1324 | /* | |
1325 | * Wipe any geometry if the size of the table changed. | |
1326 | */ | |
1327 | if (size != get_capacity(md->disk)) | |
1328 | memset(&md->geometry, 0, sizeof(md->geometry)); | |
1329 | ||
32a926da | 1330 | __set_size(md, size); |
d5816876 MP |
1331 | |
1332 | if (!size) { | |
1333 | dm_table_destroy(t); | |
1da177e4 | 1334 | return 0; |
d5816876 | 1335 | } |
1da177e4 | 1336 | |
2ca3310e AK |
1337 | dm_table_event_callback(t, event_callback, md); |
1338 | ||
1da177e4 LT |
1339 | write_lock(&md->map_lock); |
1340 | md->map = t; | |
754c5fc7 | 1341 | dm_table_set_restrictions(t, q, limits); |
1da177e4 LT |
1342 | write_unlock(&md->map_lock); |
1343 | ||
1da177e4 LT |
1344 | return 0; |
1345 | } | |
1346 | ||
1347 | static void __unbind(struct mapped_device *md) | |
1348 | { | |
1349 | struct dm_table *map = md->map; | |
1350 | ||
1351 | if (!map) | |
1352 | return; | |
1353 | ||
1354 | dm_table_event_callback(map, NULL, NULL); | |
1355 | write_lock(&md->map_lock); | |
1356 | md->map = NULL; | |
1357 | write_unlock(&md->map_lock); | |
d5816876 | 1358 | dm_table_destroy(map); |
1da177e4 LT |
1359 | } |
1360 | ||
1361 | /* | |
1362 | * Constructor for a new device. | |
1363 | */ | |
2b06cfff | 1364 | int dm_create(int minor, struct mapped_device **result) |
1da177e4 LT |
1365 | { |
1366 | struct mapped_device *md; | |
1367 | ||
2b06cfff | 1368 | md = alloc_dev(minor); |
1da177e4 LT |
1369 | if (!md) |
1370 | return -ENXIO; | |
1371 | ||
784aae73 MB |
1372 | dm_sysfs_init(md); |
1373 | ||
1da177e4 LT |
1374 | *result = md; |
1375 | return 0; | |
1376 | } | |
1377 | ||
637842cf | 1378 | static struct mapped_device *dm_find_md(dev_t dev) |
1da177e4 LT |
1379 | { |
1380 | struct mapped_device *md; | |
1da177e4 LT |
1381 | unsigned minor = MINOR(dev); |
1382 | ||
1383 | if (MAJOR(dev) != _major || minor >= (1 << MINORBITS)) | |
1384 | return NULL; | |
1385 | ||
f32c10b0 | 1386 | spin_lock(&_minor_lock); |
1da177e4 LT |
1387 | |
1388 | md = idr_find(&_minor_idr, minor); | |
fba9f90e | 1389 | if (md && (md == MINOR_ALLOCED || |
f331c029 | 1390 | (MINOR(disk_devt(dm_disk(md))) != minor) || |
17b2f66f | 1391 | test_bit(DMF_FREEING, &md->flags))) { |
637842cf | 1392 | md = NULL; |
fba9f90e JM |
1393 | goto out; |
1394 | } | |
1da177e4 | 1395 | |
fba9f90e | 1396 | out: |
f32c10b0 | 1397 | spin_unlock(&_minor_lock); |
1da177e4 | 1398 | |
637842cf DT |
1399 | return md; |
1400 | } | |
1401 | ||
d229a958 DT |
1402 | struct mapped_device *dm_get_md(dev_t dev) |
1403 | { | |
1404 | struct mapped_device *md = dm_find_md(dev); | |
1405 | ||
1406 | if (md) | |
1407 | dm_get(md); | |
1408 | ||
1409 | return md; | |
1410 | } | |
1411 | ||
9ade92a9 | 1412 | void *dm_get_mdptr(struct mapped_device *md) |
637842cf | 1413 | { |
9ade92a9 | 1414 | return md->interface_ptr; |
1da177e4 LT |
1415 | } |
1416 | ||
1417 | void dm_set_mdptr(struct mapped_device *md, void *ptr) | |
1418 | { | |
1419 | md->interface_ptr = ptr; | |
1420 | } | |
1421 | ||
1422 | void dm_get(struct mapped_device *md) | |
1423 | { | |
1424 | atomic_inc(&md->holders); | |
1425 | } | |
1426 | ||
72d94861 AK |
1427 | const char *dm_device_name(struct mapped_device *md) |
1428 | { | |
1429 | return md->name; | |
1430 | } | |
1431 | EXPORT_SYMBOL_GPL(dm_device_name); | |
1432 | ||
1da177e4 LT |
1433 | void dm_put(struct mapped_device *md) |
1434 | { | |
1134e5ae | 1435 | struct dm_table *map; |
1da177e4 | 1436 | |
fba9f90e JM |
1437 | BUG_ON(test_bit(DMF_FREEING, &md->flags)); |
1438 | ||
f32c10b0 | 1439 | if (atomic_dec_and_lock(&md->holders, &_minor_lock)) { |
1134e5ae | 1440 | map = dm_get_table(md); |
f331c029 TH |
1441 | idr_replace(&_minor_idr, MINOR_ALLOCED, |
1442 | MINOR(disk_devt(dm_disk(md)))); | |
fba9f90e | 1443 | set_bit(DMF_FREEING, &md->flags); |
f32c10b0 | 1444 | spin_unlock(&_minor_lock); |
cf222b37 | 1445 | if (!dm_suspended(md)) { |
1da177e4 LT |
1446 | dm_table_presuspend_targets(map); |
1447 | dm_table_postsuspend_targets(map); | |
1448 | } | |
784aae73 | 1449 | dm_sysfs_exit(md); |
1134e5ae | 1450 | dm_table_put(map); |
a1b51e98 | 1451 | __unbind(md); |
1da177e4 LT |
1452 | free_dev(md); |
1453 | } | |
1da177e4 | 1454 | } |
79eb885c | 1455 | EXPORT_SYMBOL_GPL(dm_put); |
1da177e4 | 1456 | |
401600df | 1457 | static int dm_wait_for_completion(struct mapped_device *md, int interruptible) |
46125c1c MB |
1458 | { |
1459 | int r = 0; | |
b44ebeb0 MP |
1460 | DECLARE_WAITQUEUE(wait, current); |
1461 | ||
1462 | dm_unplug_all(md->queue); | |
1463 | ||
1464 | add_wait_queue(&md->wait, &wait); | |
46125c1c MB |
1465 | |
1466 | while (1) { | |
401600df | 1467 | set_current_state(interruptible); |
46125c1c MB |
1468 | |
1469 | smp_mb(); | |
1470 | if (!atomic_read(&md->pending)) | |
1471 | break; | |
1472 | ||
401600df MP |
1473 | if (interruptible == TASK_INTERRUPTIBLE && |
1474 | signal_pending(current)) { | |
46125c1c MB |
1475 | r = -EINTR; |
1476 | break; | |
1477 | } | |
1478 | ||
1479 | io_schedule(); | |
1480 | } | |
1481 | set_current_state(TASK_RUNNING); | |
1482 | ||
b44ebeb0 MP |
1483 | remove_wait_queue(&md->wait, &wait); |
1484 | ||
46125c1c MB |
1485 | return r; |
1486 | } | |
1487 | ||
531fe963 | 1488 | static void dm_flush(struct mapped_device *md) |
af7e466a MP |
1489 | { |
1490 | dm_wait_for_completion(md, TASK_UNINTERRUPTIBLE); | |
52b1fd5a MP |
1491 | |
1492 | bio_init(&md->barrier_bio); | |
1493 | md->barrier_bio.bi_bdev = md->bdev; | |
1494 | md->barrier_bio.bi_rw = WRITE_BARRIER; | |
1495 | __split_and_process_bio(md, &md->barrier_bio); | |
1496 | ||
1497 | dm_wait_for_completion(md, TASK_UNINTERRUPTIBLE); | |
af7e466a MP |
1498 | } |
1499 | ||
1500 | static void process_barrier(struct mapped_device *md, struct bio *bio) | |
1501 | { | |
5aa2781d MP |
1502 | md->barrier_error = 0; |
1503 | ||
531fe963 | 1504 | dm_flush(md); |
af7e466a | 1505 | |
5aa2781d MP |
1506 | if (!bio_empty_barrier(bio)) { |
1507 | __split_and_process_bio(md, bio); | |
1508 | dm_flush(md); | |
af7e466a MP |
1509 | } |
1510 | ||
af7e466a | 1511 | if (md->barrier_error != DM_ENDIO_REQUEUE) |
531fe963 | 1512 | bio_endio(bio, md->barrier_error); |
2761e95f MP |
1513 | else { |
1514 | spin_lock_irq(&md->deferred_lock); | |
1515 | bio_list_add_head(&md->deferred, bio); | |
1516 | spin_unlock_irq(&md->deferred_lock); | |
1517 | } | |
af7e466a MP |
1518 | } |
1519 | ||
1da177e4 LT |
1520 | /* |
1521 | * Process the deferred bios | |
1522 | */ | |
ef208587 | 1523 | static void dm_wq_work(struct work_struct *work) |
1da177e4 | 1524 | { |
ef208587 MP |
1525 | struct mapped_device *md = container_of(work, struct mapped_device, |
1526 | work); | |
6d6f10df | 1527 | struct bio *c; |
1da177e4 | 1528 | |
ef208587 MP |
1529 | down_write(&md->io_lock); |
1530 | ||
3b00b203 | 1531 | while (!test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags)) { |
df12ee99 AK |
1532 | spin_lock_irq(&md->deferred_lock); |
1533 | c = bio_list_pop(&md->deferred); | |
1534 | spin_unlock_irq(&md->deferred_lock); | |
1535 | ||
1536 | if (!c) { | |
1eb787ec | 1537 | clear_bit(DMF_QUEUE_IO_TO_THREAD, &md->flags); |
df12ee99 AK |
1538 | break; |
1539 | } | |
022c2611 | 1540 | |
3b00b203 MP |
1541 | up_write(&md->io_lock); |
1542 | ||
af7e466a MP |
1543 | if (bio_barrier(c)) |
1544 | process_barrier(md, c); | |
1545 | else | |
1546 | __split_and_process_bio(md, c); | |
3b00b203 MP |
1547 | |
1548 | down_write(&md->io_lock); | |
022c2611 | 1549 | } |
73d410c0 | 1550 | |
ef208587 | 1551 | up_write(&md->io_lock); |
1da177e4 LT |
1552 | } |
1553 | ||
9a1fb464 | 1554 | static void dm_queue_flush(struct mapped_device *md) |
304f3f6a | 1555 | { |
3b00b203 MP |
1556 | clear_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags); |
1557 | smp_mb__after_clear_bit(); | |
53d5914f | 1558 | queue_work(md->wq, &md->work); |
304f3f6a MB |
1559 | } |
1560 | ||
1da177e4 LT |
1561 | /* |
1562 | * Swap in a new table (destroying old one). | |
1563 | */ | |
1564 | int dm_swap_table(struct mapped_device *md, struct dm_table *table) | |
1565 | { | |
754c5fc7 | 1566 | struct queue_limits limits; |
93c534ae | 1567 | int r = -EINVAL; |
1da177e4 | 1568 | |
e61290a4 | 1569 | mutex_lock(&md->suspend_lock); |
1da177e4 LT |
1570 | |
1571 | /* device must be suspended */ | |
cf222b37 | 1572 | if (!dm_suspended(md)) |
93c534ae | 1573 | goto out; |
1da177e4 | 1574 | |
754c5fc7 MS |
1575 | r = dm_calculate_queue_limits(table, &limits); |
1576 | if (r) | |
1577 | goto out; | |
1578 | ||
1da177e4 | 1579 | __unbind(md); |
754c5fc7 | 1580 | r = __bind(md, table, &limits); |
1da177e4 | 1581 | |
93c534ae | 1582 | out: |
e61290a4 | 1583 | mutex_unlock(&md->suspend_lock); |
93c534ae | 1584 | return r; |
1da177e4 LT |
1585 | } |
1586 | ||
1587 | /* | |
1588 | * Functions to lock and unlock any filesystem running on the | |
1589 | * device. | |
1590 | */ | |
2ca3310e | 1591 | static int lock_fs(struct mapped_device *md) |
1da177e4 | 1592 | { |
e39e2e95 | 1593 | int r; |
1da177e4 LT |
1594 | |
1595 | WARN_ON(md->frozen_sb); | |
dfbe03f6 | 1596 | |
db8fef4f | 1597 | md->frozen_sb = freeze_bdev(md->bdev); |
dfbe03f6 | 1598 | if (IS_ERR(md->frozen_sb)) { |
cf222b37 | 1599 | r = PTR_ERR(md->frozen_sb); |
e39e2e95 AK |
1600 | md->frozen_sb = NULL; |
1601 | return r; | |
dfbe03f6 AK |
1602 | } |
1603 | ||
aa8d7c2f AK |
1604 | set_bit(DMF_FROZEN, &md->flags); |
1605 | ||
1da177e4 LT |
1606 | return 0; |
1607 | } | |
1608 | ||
2ca3310e | 1609 | static void unlock_fs(struct mapped_device *md) |
1da177e4 | 1610 | { |
aa8d7c2f AK |
1611 | if (!test_bit(DMF_FROZEN, &md->flags)) |
1612 | return; | |
1613 | ||
db8fef4f | 1614 | thaw_bdev(md->bdev, md->frozen_sb); |
1da177e4 | 1615 | md->frozen_sb = NULL; |
aa8d7c2f | 1616 | clear_bit(DMF_FROZEN, &md->flags); |
1da177e4 LT |
1617 | } |
1618 | ||
1619 | /* | |
1620 | * We need to be able to change a mapping table under a mounted | |
1621 | * filesystem. For example we might want to move some data in | |
1622 | * the background. Before the table can be swapped with | |
1623 | * dm_bind_table, dm_suspend must be called to flush any in | |
1624 | * flight bios and ensure that any further io gets deferred. | |
1625 | */ | |
a3d77d35 | 1626 | int dm_suspend(struct mapped_device *md, unsigned suspend_flags) |
1da177e4 | 1627 | { |
2ca3310e | 1628 | struct dm_table *map = NULL; |
46125c1c | 1629 | int r = 0; |
a3d77d35 | 1630 | int do_lockfs = suspend_flags & DM_SUSPEND_LOCKFS_FLAG ? 1 : 0; |
2e93ccc1 | 1631 | int noflush = suspend_flags & DM_SUSPEND_NOFLUSH_FLAG ? 1 : 0; |
1da177e4 | 1632 | |
e61290a4 | 1633 | mutex_lock(&md->suspend_lock); |
2ca3310e | 1634 | |
73d410c0 MB |
1635 | if (dm_suspended(md)) { |
1636 | r = -EINVAL; | |
d287483d | 1637 | goto out_unlock; |
73d410c0 | 1638 | } |
1da177e4 LT |
1639 | |
1640 | map = dm_get_table(md); | |
1da177e4 | 1641 | |
2e93ccc1 KU |
1642 | /* |
1643 | * DMF_NOFLUSH_SUSPENDING must be set before presuspend. | |
1644 | * This flag is cleared before dm_suspend returns. | |
1645 | */ | |
1646 | if (noflush) | |
1647 | set_bit(DMF_NOFLUSH_SUSPENDING, &md->flags); | |
1648 | ||
cf222b37 AK |
1649 | /* This does not get reverted if there's an error later. */ |
1650 | dm_table_presuspend_targets(map); | |
1651 | ||
32a926da MP |
1652 | /* |
1653 | * Flush I/O to the device. noflush supersedes do_lockfs, | |
1654 | * because lock_fs() needs to flush I/Os. | |
1655 | */ | |
1656 | if (!noflush && do_lockfs) { | |
1657 | r = lock_fs(md); | |
1658 | if (r) | |
f431d966 | 1659 | goto out; |
aa8d7c2f | 1660 | } |
1da177e4 LT |
1661 | |
1662 | /* | |
3b00b203 MP |
1663 | * Here we must make sure that no processes are submitting requests |
1664 | * to target drivers i.e. no one may be executing | |
1665 | * __split_and_process_bio. This is called from dm_request and | |
1666 | * dm_wq_work. | |
1667 | * | |
1668 | * To get all processes out of __split_and_process_bio in dm_request, | |
1669 | * we take the write lock. To prevent any process from reentering | |
1670 | * __split_and_process_bio from dm_request, we set | |
1671 | * DMF_QUEUE_IO_TO_THREAD. | |
1672 | * | |
1673 | * To quiesce the thread (dm_wq_work), we set DMF_BLOCK_IO_FOR_SUSPEND | |
1674 | * and call flush_workqueue(md->wq). flush_workqueue will wait until | |
1675 | * dm_wq_work exits and DMF_BLOCK_IO_FOR_SUSPEND will prevent any | |
1676 | * further calls to __split_and_process_bio from dm_wq_work. | |
1da177e4 | 1677 | */ |
2ca3310e | 1678 | down_write(&md->io_lock); |
1eb787ec AK |
1679 | set_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags); |
1680 | set_bit(DMF_QUEUE_IO_TO_THREAD, &md->flags); | |
2ca3310e | 1681 | up_write(&md->io_lock); |
1da177e4 | 1682 | |
3b00b203 MP |
1683 | flush_workqueue(md->wq); |
1684 | ||
1da177e4 | 1685 | /* |
3b00b203 MP |
1686 | * At this point no more requests are entering target request routines. |
1687 | * We call dm_wait_for_completion to wait for all existing requests | |
1688 | * to finish. | |
1da177e4 | 1689 | */ |
401600df | 1690 | r = dm_wait_for_completion(md, TASK_INTERRUPTIBLE); |
1da177e4 | 1691 | |
2ca3310e | 1692 | down_write(&md->io_lock); |
6d6f10df | 1693 | if (noflush) |
022c2611 | 1694 | clear_bit(DMF_NOFLUSH_SUSPENDING, &md->flags); |
94d6351e | 1695 | up_write(&md->io_lock); |
2e93ccc1 | 1696 | |
1da177e4 | 1697 | /* were we interrupted ? */ |
46125c1c | 1698 | if (r < 0) { |
9a1fb464 | 1699 | dm_queue_flush(md); |
73d410c0 | 1700 | |
2ca3310e | 1701 | unlock_fs(md); |
2e93ccc1 | 1702 | goto out; /* pushback list is already flushed, so skip flush */ |
2ca3310e | 1703 | } |
1da177e4 | 1704 | |
3b00b203 MP |
1705 | /* |
1706 | * If dm_wait_for_completion returned 0, the device is completely | |
1707 | * quiescent now. There is no request-processing activity. All new | |
1708 | * requests are being added to md->deferred list. | |
1709 | */ | |
1710 | ||
cf222b37 | 1711 | dm_table_postsuspend_targets(map); |
1da177e4 | 1712 | |
2ca3310e | 1713 | set_bit(DMF_SUSPENDED, &md->flags); |
b84b0287 | 1714 | |
2ca3310e AK |
1715 | out: |
1716 | dm_table_put(map); | |
d287483d AK |
1717 | |
1718 | out_unlock: | |
e61290a4 | 1719 | mutex_unlock(&md->suspend_lock); |
cf222b37 | 1720 | return r; |
1da177e4 LT |
1721 | } |
1722 | ||
1723 | int dm_resume(struct mapped_device *md) | |
1724 | { | |
cf222b37 | 1725 | int r = -EINVAL; |
cf222b37 | 1726 | struct dm_table *map = NULL; |
1da177e4 | 1727 | |
e61290a4 | 1728 | mutex_lock(&md->suspend_lock); |
2ca3310e | 1729 | if (!dm_suspended(md)) |
cf222b37 | 1730 | goto out; |
cf222b37 AK |
1731 | |
1732 | map = dm_get_table(md); | |
2ca3310e | 1733 | if (!map || !dm_table_get_size(map)) |
cf222b37 | 1734 | goto out; |
1da177e4 | 1735 | |
8757b776 MB |
1736 | r = dm_table_resume_targets(map); |
1737 | if (r) | |
1738 | goto out; | |
2ca3310e | 1739 | |
9a1fb464 | 1740 | dm_queue_flush(md); |
2ca3310e AK |
1741 | |
1742 | unlock_fs(md); | |
1743 | ||
1744 | clear_bit(DMF_SUSPENDED, &md->flags); | |
1745 | ||
1da177e4 | 1746 | dm_table_unplug_all(map); |
cf222b37 AK |
1747 | r = 0; |
1748 | out: | |
1749 | dm_table_put(map); | |
e61290a4 | 1750 | mutex_unlock(&md->suspend_lock); |
2ca3310e | 1751 | |
cf222b37 | 1752 | return r; |
1da177e4 LT |
1753 | } |
1754 | ||
1755 | /*----------------------------------------------------------------- | |
1756 | * Event notification. | |
1757 | *---------------------------------------------------------------*/ | |
60935eb2 MB |
1758 | void dm_kobject_uevent(struct mapped_device *md, enum kobject_action action, |
1759 | unsigned cookie) | |
69267a30 | 1760 | { |
60935eb2 MB |
1761 | char udev_cookie[DM_COOKIE_LENGTH]; |
1762 | char *envp[] = { udev_cookie, NULL }; | |
1763 | ||
1764 | if (!cookie) | |
1765 | kobject_uevent(&disk_to_dev(md->disk)->kobj, action); | |
1766 | else { | |
1767 | snprintf(udev_cookie, DM_COOKIE_LENGTH, "%s=%u", | |
1768 | DM_COOKIE_ENV_VAR_NAME, cookie); | |
1769 | kobject_uevent_env(&disk_to_dev(md->disk)->kobj, action, envp); | |
1770 | } | |
69267a30 AK |
1771 | } |
1772 | ||
7a8c3d3b MA |
1773 | uint32_t dm_next_uevent_seq(struct mapped_device *md) |
1774 | { | |
1775 | return atomic_add_return(1, &md->uevent_seq); | |
1776 | } | |
1777 | ||
1da177e4 LT |
1778 | uint32_t dm_get_event_nr(struct mapped_device *md) |
1779 | { | |
1780 | return atomic_read(&md->event_nr); | |
1781 | } | |
1782 | ||
1783 | int dm_wait_event(struct mapped_device *md, int event_nr) | |
1784 | { | |
1785 | return wait_event_interruptible(md->eventq, | |
1786 | (event_nr != atomic_read(&md->event_nr))); | |
1787 | } | |
1788 | ||
7a8c3d3b MA |
1789 | void dm_uevent_add(struct mapped_device *md, struct list_head *elist) |
1790 | { | |
1791 | unsigned long flags; | |
1792 | ||
1793 | spin_lock_irqsave(&md->uevent_lock, flags); | |
1794 | list_add(elist, &md->uevent_list); | |
1795 | spin_unlock_irqrestore(&md->uevent_lock, flags); | |
1796 | } | |
1797 | ||
1da177e4 LT |
1798 | /* |
1799 | * The gendisk is only valid as long as you have a reference | |
1800 | * count on 'md'. | |
1801 | */ | |
1802 | struct gendisk *dm_disk(struct mapped_device *md) | |
1803 | { | |
1804 | return md->disk; | |
1805 | } | |
1806 | ||
784aae73 MB |
1807 | struct kobject *dm_kobject(struct mapped_device *md) |
1808 | { | |
1809 | return &md->kobj; | |
1810 | } | |
1811 | ||
1812 | /* | |
1813 | * struct mapped_device should not be exported outside of dm.c | |
1814 | * so use this check to verify that kobj is part of md structure | |
1815 | */ | |
1816 | struct mapped_device *dm_get_from_kobject(struct kobject *kobj) | |
1817 | { | |
1818 | struct mapped_device *md; | |
1819 | ||
1820 | md = container_of(kobj, struct mapped_device, kobj); | |
1821 | if (&md->kobj != kobj) | |
1822 | return NULL; | |
1823 | ||
4d89b7b4 MB |
1824 | if (test_bit(DMF_FREEING, &md->flags) || |
1825 | test_bit(DMF_DELETING, &md->flags)) | |
1826 | return NULL; | |
1827 | ||
784aae73 MB |
1828 | dm_get(md); |
1829 | return md; | |
1830 | } | |
1831 | ||
1da177e4 LT |
1832 | int dm_suspended(struct mapped_device *md) |
1833 | { | |
1834 | return test_bit(DMF_SUSPENDED, &md->flags); | |
1835 | } | |
1836 | ||
2e93ccc1 KU |
1837 | int dm_noflush_suspending(struct dm_target *ti) |
1838 | { | |
1839 | struct mapped_device *md = dm_table_get_md(ti->table); | |
1840 | int r = __noflush_suspending(md); | |
1841 | ||
1842 | dm_put(md); | |
1843 | ||
1844 | return r; | |
1845 | } | |
1846 | EXPORT_SYMBOL_GPL(dm_noflush_suspending); | |
1847 | ||
1da177e4 LT |
1848 | static struct block_device_operations dm_blk_dops = { |
1849 | .open = dm_blk_open, | |
1850 | .release = dm_blk_close, | |
aa129a22 | 1851 | .ioctl = dm_blk_ioctl, |
3ac51e74 | 1852 | .getgeo = dm_blk_getgeo, |
1da177e4 LT |
1853 | .owner = THIS_MODULE |
1854 | }; | |
1855 | ||
1856 | EXPORT_SYMBOL(dm_get_mapinfo); | |
1857 | ||
1858 | /* | |
1859 | * module hooks | |
1860 | */ | |
1861 | module_init(dm_init); | |
1862 | module_exit(dm_exit); | |
1863 | ||
1864 | module_param(major, uint, 0); | |
1865 | MODULE_PARM_DESC(major, "The major number of the device mapper"); | |
1866 | MODULE_DESCRIPTION(DM_NAME " driver"); | |
1867 | MODULE_AUTHOR("Joe Thornber <dm-devel@redhat.com>"); | |
1868 | MODULE_LICENSE("GPL"); |